1 {scene: Platform 9 3/4}
1 Ron: Well Hermione, it's our last year at Hogwarts and Harry has run off to fight Voldemort.
2 Ron: We need a new student to make up our tight-knit and adventure-seeking cadre of three.
3 Ron: What do you think? Neville? Luna? Seamus? Parvati?
4 Hermione: {pointing at an incredibly handsome student walking past} What about Will, the exchange student?
4 Ron: Capital idea!

Yeah, I know at the end of book six Ron and Hermione decide to join Harry in his departure from Hogwarts.
But this isn't meant to be canon - this is Will's fan-fic. He's clearly changed the narrative, and in more
ways than that minor detail...

2016-07-06 Rerun commentary: I'm also not sure Ron would know the word "cadre" if this were meant to be following the canon.

Also, I'm not really sure where Will is an exchange student from. Australia, I guess...